Entry doors, sliding patio doors, hinged patio doors, and storm doors, fitted to the opening. This page covers Gaithersburg, plus Germantown, Clarksburg, and Damascus: 16 ZIP codes in Montgomery County.
The slab, glass, and hardware are specced to the elevation at the estimate.
Composite slabs and glass options, with hardware and sidelights specced to the elevation.
Wide glass that stays out of the room, on a track that does not grind.
French and single-leaf doors, in-swing or out-swing.
The extra layer that lets you open the entry without inviting the weather in.
Light or air at the edges means the weatherstrip and frame no longer seal.
Doors that rub, stick, or need a shoulder to close.
Condensation between the panes of a door lite or sidelight.
Locks that do not line up, or latches that will not catch.
ExteriorMax installs roofing, siding, windows, gutters, doors, and decks in Gaithersburg, Maryland under MD 142964. Maryland, Virginia, West Virginia, and Pennsylvania are authorized service areas. The business address is 6301 Ivy Ln, Suite 120, Greenbelt, MD 20770.
The ZIP codes below are the zone list that names Gaithersburg, along with Germantown, Clarksburg, and Damascus. They are not a city-limit map of Gaithersburg alone.
Photos on this page are examples of ExteriorMax work and the products we install. They are not a job at a specific address.
Gaithersburg, Germantown, Clarksburg, Damascus. Montgomery County. Zone MD-MOCO-I270. ZIP codes: 20871, 20872, 20874, 20875, 20876, 20877, 20878, 20879, 20880, 20882, 20883, 20884, 20885, 20886, 20898, 20899.
From 2025-11-11 through 2026-11-11, National Weather Service severe reports for Montgomery County include this headline: 60 mph winds recorded in Montgomery County. That is a county record. It does not mean every home in these ZIP codes experienced that weather. Wind-driven rain is why every door install is pan-flashed. We check the opening, not the county headline.
$0 down financing for qualified homeowners. Plans are walked at the inspection. A small deposit holds the schedule. Financing details.
Yes. This page covers Gaithersburg, plus Germantown, Clarksburg, and Damascus: 16 ZIP codes in Montgomery County under MD 142964.
Entry doors, Sliding patio, Hinged patio, Storm doors. The slab, glass, and hardware are specced to the elevation at the estimate.
Specced to the house, Old unit out, opening checked, Pan-flashed, foamed, and sealed, Adjusted and walked through.
Permit rules differ by county. ExteriorMax handles the permit and HOA packet for the job. We do not publish a separate permit fee for Gaithersburg.
$0 down financing for qualified homeowners. Plans are walked at the inspection. A small deposit holds the schedule.
Also in Gaithersburg: Roofing in Gaithersburg · Siding in Gaithersburg · Windows in Gaithersburg · Gutters in Gaithersburg · Decks in Gaithersburg.
Company-wide doors page · Entry, patio, and storm doors · Gaithersburg overview
Clarksburg doors · Damascus doors · Germantown doors · Barnesville doors · Bethesda doors · Burtonsville doors · Chevy Chase doors · Dickerson doors
Gaithersburg, plus Germantown, Clarksburg, and Damascus. ExteriorMax installs roofing, siding, windows, gutters, doors, and decks in Gaithersburg, Maryland under MD 142964. Maryland, Virginia, West Virginia, and Pennsylvania are authorized service areas. The business address is 6301 Ivy Ln, Suite 120, Greenbelt, MD 20770.